std::mutex::unlock

 

C++

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Thread support library

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thread (C++11)
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mutex (C++11) timed_mutex (C++11)	recursive_mutex (C++11) recursive_timed_mutex (C++11)
Generic lock management
lock_guard (C++11) unique_lock (C++11) defer_lock_t try_to_lock_t adopt_lock_t (C++11) (C++11) (C++11)	lock (C++11) try_lock (C++11) defer_lock try_to_lock adopt_lock (C++11) (C++11) (C++11)
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std::mutex

Member functions

mutex::mutex

Locking

mutex::lock

mutex::try_lock

mutex::unlock

Native handle

mutex::native_handle

 

void unlock();		(since C++11)

Unlocks the mutex.

Parameters

(none)

Return value

(none)

Example

This example shows lock, try_lock and unlock in action

#include <iostream>
#include <mutex>
 
int main()
{
    std::mutex test;
    if (test.try_lock()==true)
        std::cout << "lock acquired" << std::endl;
    else
        std::cout << "lock not acquired" << std::endl;
    test.unlock();	//now unlock the mutex
    test.lock();	//to lock it again
    if (test.try_lock())  //true can be left out
        std::cout << "lock acquired" << std::endl;
    else
        std::cout << "lock not acquired" << std::endl;
    test.lock(); //and now the finale (a block)
}

Output:

lock acquired
lock not acquired
(program hangs)

See also

lock	locks the mutex, blocks if the mutex is not available (public member function)
try_lock	tries to lock the mutex, returns if the mutex is not available (public member function)